After a shaky start to the Arizona Fall League, right-hander Sam Gaviglio went back to what has always worked for him. He simplified his game plan, relying more on his fastball.

It has proved to be a good adjustment. In his first three starts in the AFL, Gaviglio had a 7.10 ERA in 12 2/3 innings. In his last two, Gaviglio has thrown 10 scoreless innings and allowed just four hits.

"I'm keeping it simple," Gaviglio said. "I think I was trying to do too much and not throwing my sinker enough."

That approach worked again Tuesday night as he threw five scoreless innings and helped Salt River to an 8-0 victory against Mesa at Salt River Fields at Talking Stick in Scottsdale. The win brought the Rafters within 1 1/2 games of the Solar Sox in the East Division standings with eight games to play.

As Gaviglio's scoreless-innings streak reached 10 on Tuesday, he allowed just two hits and a walk against one of the league's most powerful offenses. The Cardinals farmhand was also the beneficiary of a seven-run third inning, which he said helped relax him on the mound.

"I felt pretty good, especially once we got that lead," Gaviglio said. "I wanted to get ahead of hitters."

Once Gaviglio left the game, Henry Garcia, Tyler Matzek, Anthony Ferrara and Matt Stites each threw a scoreless inning to complete the four-hit shutout. It was the first time the Solar Sox were shut out this season. Albert Almora, Tyler Collins, Matt Skole and Adrian Nieto each had a hit.

Mesa's struggles weren't limited to the batter's box. The Solar Sox committed five errors, including three in the Rafters' seven-run third. All of those runs were unearned.

The inning began with an error on shortstop Dixon Machado and didn't get any better for the Solar Sox. They committed two more errors and the Rafters batted around against starter Dallas Beeler before he was relieved with two outs by left-hander Kenny Faulk.

Faulk gave up a two-run double to Jacob Wilson, the only extra-base hit of the inning, before getting a strikeout to retire Salt River. In all, the Rafters sent 11 batters to the plate and recorded five hits in the inning.

Gaviglio was happy to see the Rafters offense keep piling runs on during the inning.

"I think it's always great when you get a big lead," he said. "Then I just had to attack the zone and make the hitters hit it instead of making it too fine."

Stephen Piscotty, the Cardinals' No. 7 prospect, went 2-for-4 with a run and an RBI. Jake Lamb, the D-backs' No. 11 prospect, went 0-for-3 with a run and an RBI, ending his 12-game hitting streak. Lamb came within one game shy of matching this season's longest hitting streak in the AFL, held by Surprise center fielder Tyler Naquin.

Tuesday's game was the first of a five-game testing period in the AFL of MLB's proposed instant replay system. There were four reviews, none in a pivotal moment. All four reviews upheld the umpire's original call.

Gaviglio said he thought it went well, though it interrupted the flow of the game.

"It's always nice to get the call right," Gaviglio said. "But I felt it kind of killed the momentum of the game, especially since we knew the outcome.

"You get a quick out and then you're sitting there on the mound waiting for them to make a call on the play or vice versa."

Gaviglio won't have to worry about instant replay when he takes the mound next week. He will be able to focus on trying to continue his hot streak and focus on what the Cardinals wanted him to improve during the fall.

"My emphasis is my offspeed," Gaviglio said. "That's something the Cardinals want me to work on, and that needs to get better. Also, my fastball command and making sure I'm getting ahead of hitters."

Teddy Cahill is a reporter for MLB.com. Follow him on Twitter at @tedcahill. This story was not subject to the approval of Major League Baseball or its clubs.